Guardian Application Conversion Guide

Being Opened by and Communicating With a High-PIN Requester
Converting C Applications
096047 Tandem Computers Incorporated 5–29
FILE_GETRECEIVEINFO_ returns information in the 17-word message_info
parameter, which has the format shown in Table 5-1. The ZSYSC file contains a
structure that you can use for the message_info format.
Table 5-1. FILE_GETRECEIVEINFO_ message_info Parameter Format
Word Description
0 I/O type for the message:
0 = A system message was sent.
1 = The sender called WRITE[X].
2 = The sender called READ[X].
3 = The sender called WRITEREAD[X].
1 The maximum reply count in bytes
2 The message tag identifying the message
3 The file number for the message
4 through 5 The sync ID for the message
6 through 15 The process handle of the process sending the message
16 The open_label from a previous reply (or -1 if unavailable or for a C-series message)
Reading and Processing Open and Close System Messages
To monitor an opener, your server might read the C-series -30 (Process open) and -31
(Process close) system messages from $RECEIVE.
To monitor a high-PIN process, convert your server to read the D-series -103 (Process
open) and -104 (Process close) system messages. When your server is opened or closed
by a process pair, it receives a process-open or process-close message from each
process of the pair.
If you call the RECEIVEINFO or LASTRECEIVE procedure to obtain information
about the process-open or process-close message, convert the call into a call to the
FILE_GETRECEIVEINFO_ procedure as described under “Getting Information About
System Messages,” earlier in this section.
After calling FILE_GETRECEIVEINFO_, update your opener table using the process
handle rather than the process ID to identify the opener.